Suicide risk among adults with mental health emergency department visits with and without suicidal symptoms

Objective:
The authors describe risk factors and suicide rates during the year following discharge from mental health emergency department (ED) visits by adults with suicide attempts, suicidal ideation, or neither.
Methods:
National cohorts of patients with mental health ED visits for suicide attempts or self-harm (n=55,323), suicidal ideation (n=435,464), or other mental health visits (n=9,144,807) from 2008–2018 Medicaid data were followed for suicide for 1 year after discharge. Suicide rates per 100,000 person-years were determined from National Death Index data. Poisson regression models, adjusted for age, sex, and race/ethnicity, estimated suicide rate ratios (RR). Suicide standardized mortality ratios (SMRs) were estimated from National Vital Statistics System data.
Results:
Suicide rates per 100,000 person-years were 325.4 for suicide attempt or self-harm visits (RR=5.51, 95%CI:4.64–6.55), 156.6 for suicidal ideation visits (RR=2.59, 95%CI:2.34–2.87), and 57.0 for the other mental health ED visits (1.0, reference). Compared to expected suicide general population rates, SMRs were 18.2 (95%CI:13.0–23.4) for suicide attempt or self-harm patients, 10.6 (95%CI:9.0–12.2) for suicidal ideation patients, and 3.2 (95%CI:3.1–3.4) for other ED mental health patients. Among patients with suicide attempt ED visits in the 180 days before their index mental health ED visit, suicide rates per 100,000 person-years were 687.2 (95% CI:396.5–978.0) for attempt or self-harm visits, 397.4 (95%CI: 230.6–564.3) for ideation visits, and 328.4 (95%CI:241.5–415.4) for other mental health visits.
Conclusion:
In the year following discharge, emergency department patients with suicide attempts or self-harm, especially repeated attempts, have a high risk of suicide.